A lot of Southern hip-hop is all about paradigms and approaches; the laws of the rest of the world really do apply once you cross the Mason-Dixon line. Even the left-of-center entries, like Timbaland-produced newcomer Bubba Sparxxx (whose current video burlesques both Southern dirty white-boy culture and the neighborhood feel of Cash Money's early vids) and OutKast, who are so out there they damn near have their own genome, can claim connection to a particular crew, sphere of influence, and/or aesthetic approach.

These connections often cross geographic boundariesAtlanta may be the spiritual home of "crunk," for example, but artists from Memphis and Louisiana get the concept well enough to come up with their own floor- shattering tracks.

Some crews, like Cash Money, come up with more than others. Two years ago, depending on where you lived, you could tell the time by when Cash Money records were coming on the radio. Noon"Back That Azz Up." Quarter past"Tha Block Is Hot." Half past"Follow Me Now." It's different now, for sure, but Mannie Fresh's beat wizardry allows members of the Cash Money crew to release consistently interesting discs without ever leaving the thematic confines of the Magnolia Projects.

On Juvenile's Project English Mannie drops a mid-'70s Funkadelic break into "4 Minutes" and a pop-reggae vocal hook into "Sunshine." Compare this Mannie with the one who shows up on the extended tracks on Platinum Instrumentals, which includes sans-vocals versions of hits like "#1 Stunna," "Ha," and "Bling Bling." If you listen hard enough, you'll hear some of the same Mannie-isms that show up on Project English. "Set It Off" 's lead-footed stomp, for example, is a distant relative to "Tha Block Is Hot." Fresh, however, makes you look at his free hand, via shiny decorations (a puckish Dragnet reference, say), and glossy digital thud, demonstrating his particular skill at finding new tangents within a familiar framework.

Juvie works the same way, using his musically slanguistic vocals to turn ordinary chants and themes into stick-into-your-brain ones (as on "Mama Got Ass," a round-the-way take on female heredity). And more power to any verbalist who can make lines like "my nuts heavy/and I like it from the back so keep your butt steady" tolerable.

While Cash Money make albums as if their families were being held for ransom, the Dungeon Family (the catchall term for the Organized Noize/OutKast/Parental Advisory orbit) offer a more leisurely pace. Society of Soul, for example, has been teasing folks for a while with the promise of a follow-up to 1995's brilliant Brainchild.

Longtime Dungeon soldier Backbone lets his voice take center stage on his long-awaited solo disc, Concrete Law. Which isn't a problem, considering that his midrangey, Rémy Martin-soaked timbres can fill up a track pretty quick. Too often, though, they don't have a whole lot to lie against. Organized bless him with some engaging tracks, though: the rock-choppy "Like This," the ominous, Cee-Lo-spiced "Lord Have Mercy," the loping single "5 Deuce 4 Tre," and the Bootsy-ish "Believe That," arguably the disc's strongest track. But less, sometimes, is, well, just less. The repetitive "Jump Back" and spare offerings like "Dungeon Ratz" and "Concrete Law" leave you wishing Backbone had just a bit more tissue on his vertebrae.

The newest branch on the Dungeon tree, OutKast's Aquemini Records, landed one cap feather with Slimm Calhoun's The Skinny, which spawned the modest hit "It's OK," a kookily infectious ode to overeager groupies. OutKast's Earthtone III team handled the production, but one has to resist the temptation to compare it to Stankoniawhich is like comparing a new jazz sax album to A Love Supreme. "It's OK" 's quirky Lollipop Kids hook and bugged-out vocals make the comparison even more tempting, especially considering Andre 3000's Lewis Carroll-ish turn in the song's video. Nothing else on The Skinny is quite this catchy, though souladelic groovers like "Piece of the Pie" and "Timelock" come close.

Dungeon-associated projects typically graft ATL-style playa-isms to forward-thinking sonics, proving strip clubs can truly be a source for musical inspiration (hello Big Boi). But sonics associated with the Memphis-based Three 6 Mafia/Hypnotize Minds crew typically cross the line into sheer hardcore bombast. Despite this stylistic consistency, it's tempting to read Gangsta Boo in the context of take-no-shit-talkin Suuthin honeys like, say, Trina. But that approach requires you to ditch aesthetics and break things down by gender. Truth be told, Boo shares more conceptual territory with the rest of her Memphis's Three 6/Hypnotize Minds compadres than she does with females from other cliques. Her sophomore release features all the DJ Paul/Juicy J. hallmarks: spare, low-BPM rhythms, simplistic chants ("you say fuck me/I say fuck you"lobotomize me, please!) and narcotically repetitive, slasher-flick textures. On her sophomore release, Both Worlds *69, she flexes many of the same psycho-thug flavors as her mates. For Boo (a/k/a Lola Mitchell), having pussy so good that it tickles you when you walk is good only if it allows you to talk shit with impunity. Her persona is a comfortable fit in a rap coterie whose song titles often read like novelty T-shirt slogans ("Weak Azz Bitch," "Tear Da Club Up"). But while Boo's serrated raps make her various guises enjoyable (a stripper in "Get Your Broke Ass Out," an ego-crumbling lover in "I Faked It"), they are, for the most part, variations on a theme. She fucks "like it's for pay," shells cheap men, and saves the shrapnel for "chickenhead motherfuckinass 'hos." It's over-the-top for sureoften sounding like the soundtrack to a foreign-animation thug-life spoof directed by Coonskin-era Ralph Bakshi. But like all burlesques, the routine runs down a bit over the course of an album.

Three 6 Mafia, Lil Jon, and Pastor Troy share methods and raison d'êtrein fact, Three 6 are among a rack of all-star guests on Lil Jon & the Eastside Boyz's Put Yo Hood Up (and on a disc peppered with bludgeoning catchphrase changes like "fuck that shit" and " 'ho-ass nigga," they fit right in). They just go about their business in different ways. If Three 6's production style goes down best with a bottle of Robitussin and Hellraiser, Lil Jon and Pastor Troy are all you need for a players' night out in the ATL, where the get crunk/get drunk/get a private dance triumvirate is the club-hopper's version of the triple double.

Jon, best known as the inventor of the term crunk (as well as the mastermind behind So So Def's Bass All-Stars) employs the old bait and switch: Catch your attention with a series of muscle-bound Southern electro tracks, then lock it down with sparkling guest verses (see Ludacris's deliciously rubato turn on the hit "Bia Bia," and M.O.P.'s manic scenery-chewing on "Heads Off"). Jon also has more than one pitch in his arsenalhe serves up pimp-rolling tracks fronted by Eightball and MJG and Too Short.

To non-Southerners, Troy is best known as the dude who called out Master P (on "No Mo Play in Ga," re-released on Face Off along with some other previously indie material). Like Three 6, he favors lean beatology and gothic textures, but it's Troy's delivery that keeps you throwing your hands up through the metalloid crush of tunes like "This Tha City." He tackles Southern-thug clichés, like the obligatory r&b interpolation (New Edition on "Can You Stand the Game"), more convincingly than most; in "Prayer" and "O Father," the minister's son even manages to make a "playa confessional" sound genuine. The context reminds me of one of my minister's takes on hardcore entertainers name-checking God: "They can praise Him, but they can't worship Him." But that's not the pointlike Lil Jon, and more than a few of his other Southern brethren, Troy's aiming for that grossly reactive section of the brain that governs activities below chest level. Which is where most pop music aims anyway, though Southern artists tend to be more upfront about itleaving complaints to the wallflowers while making sure everybody else stays on the grind.